Automatic electric switch.



L. A. M. PHELAN. AUTOMATIC ELECTRIC SWITCH.

APPLICATION FILED SEPT-27,1915.

Patented Oct. 22, 1918.

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L. A. M. PHELAN.

AUTOMATIC ELECTRIC SWITCH.

APPLICATION FILED saw-27.1915.

11,282,123. Patented Oct 1918.

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AUTOMATIC ELECTRIC SWITCH.

Specification of Letters Patent,v Patented Oct- 22, 1918.

Application filed September 27, 1915. Serial No. 52,857.

To all tchom it may concern:

a citizen of the United States, residing at 232 E. Erie street, in Chicago, county of tubes, ending in a gap near one end in each Cook, and State of Illinois, have invented new and useful Improvements in Automatic Electric Switches, of which the following is a specification.

This invention relates to automatic electric switches adapted particularly for use in connection with lntermitt'ently flashing elec tric signs, and other electrical devices, where the need is for a device to automatically close andopen a circuit or circuits at the required intervals. One of the objects of the invention is to provide a device of such nature which shall be simple and cheap in construction and effective in operation, with no small or delicate parts requiring frequent adjustment or replacement, or liable to derangement; and which shall operate with a minimum amount of care and-attention, and upon a practically negligible current consumption. Such a device, briefly described, comprises a pain of tubes, preferably of glass, which are arranged parallel to each other and designed to oscillate together about a horizontal pivot. Terminal wires,

which are suitably connected to theexternal.

circuits, are fused through the walls of the tube; and in each tube'also is a quantity'of mercury, which, in the oscillations of the tubes, will run back and forth 'and make and break the circuits across these gaps. The pair of tubes is oscillated by a solenoid which is cut into and outof a shunt circuit through one of the tubes; and in this latter tube also is a restricted passage in the middle of the tube to retard the mercury in its flow back and forth and measure the intervals of time between oscillationsthis tube being in effect an hour-glass.. The other tube has no restricted'passage andoperates as a simpleswitch to open and close the main cir I ,cuit through the sign or other device; and

both tubes may be filled with nitro en or other. inert gas, but are preferab y exhausted, to prevent oxidation of the mercury through arcing.

A device embodying the principles of this It is closed at both ends, and through each end is fused a wire terminal, and 56,

device in front Fig. 3 is an enlarged axial section through the upper of the two circuit-closing tubes comprising a part of the device.

Fig. 4 is a similar section through the lower tube.

Fig. 5 is a wiring diagram of the complete device. r

Fig. 6 is anend view of the device showing the clip 14.

As shown in said drawings, in Figs. 1 to 5 inclusive, an upper and a lower circuit closing tube are illustrated at 8 and 10 respectively. These tubes are securedvto'a bar 11, of insulating material, by means of two pairs of metal clips, 14 and 15, and 16 and 17 respectively; each tube beiiig fitted with permanent metal caps, 20', over its ends, which are snapped into the clips. The insulating bar 11 is pivoted on a horizontal pivot pin or screw 25 which is secured in a suitable panel board 26, and, by means of an integral metal strip 27, one of the clips 16, securing the lower tube, is electrically connected to this screw. The adjacent clip 14, securing the upper tube, is connected through a similar strip 30 to a Wire 31, which extends through an opening 34 through the panel board, and thence to a binding post 35 on the back of the board. The other two adjacent clips, 15 and 17, are similarly connected together, as indicated at 38, and thence through .a similar wire 39, extending through a second opening 40, to a corresponding binding post 45. At the upper part of the panel board 26, and to one side of its vertical center line, is. arranged a solenoid 48, with a core 49 adapted to be. pulled int the coil by the energizin of its winding; and such core is connecte to the insulating bar 11 by a link 50 so that the movements of the solenoid core may oscillate the pair of tubes. One end of the solenoid winding is connected through a wire 51 to other heat-resisting and insulating material,

which will not be acted on by the contents of the tube, but is preferably made of glass.

which is connected to the metal cap over that end. The ends of the two terminals are separated a small distance to form a gap v end the tube and open the circuit.

. into the en vthe area of contact, each wire is formed into I acoil at its free end, as shown, and in order to protect the tube against the heat of arcing, a sleeve 62, of porcelain, mica, orthe like may be interposed between the circuit I t gap and the wall of the tube; although ordinarily this may not be necessary, sinbe the vacuum in the tube will effectively insulate its wall against heat. Y

The lower tube 10'is also partly filled with mercury, 70, but is made with arestricted passage 72 in the middle to retard the flow back and forth; and in one end of the tube are two terminals with a circuit gap .7 3 between them,'formed by'fusing a wire 74 throughthe .adjacentend of the tube, and another wire 75 through the wall of the tube; the latter wire leading to the metal cap 20 over the opposite end ,of the tube.

Although it is believed that mercury is the best conductor to use in the two tubes it might be desirable in some instances to' use in one or both tubes a metallic element/in finely divided particles which is, not too easily fused by the heat of arcing, such as carbon, which might perhaps be timed to run through the lower tube more slowly than would be practicable with mercury.

When the device is assembled, the two tubes are arranged with their circuit gaps at adjacent ends, and below' the solenoid 48; and the pair of tubes is so balanced that this end will always be heavier, even when all of the mercury is in the other end of the device. To aid in balancin the device, there may also be provided a epending arm car ing an adjustable counter-weight 81. A stop 82 limits the downward movement of the heavy end of the device, and its movement in the opposite direction is limited by the limit 0f 1movement of the solenoid core into the CO1 v The operation of the device is as follows:

With the device normally in the position shown, with the heavy end of the pair of tubes down, and the mercury closing the two circuit gaps, current is led from one of the line wires, 90, through the wire 39-and clip 17 into the upper end of the lower tube, thence through the tube, by means of the mercury in it, to the clip 16, to the pivot screw 25, throu h the wire 51 to the solenoid,

and through t e latter; returning throu h the line wire 91. This is a shunt c1rcuit,t e current strength being determined by the resistance in the solenoid 48. At the same time the main circuit is closed through the wires 90 and 39, the clip 15, the upper tube with its mercury bridging the circuit gap,

the metal parts 14 and 30 to the wire 31, and

thence through a wire and throu h the bank of lamps, or other load 100, ig. 5) back to the line wire 91. But as soon as the solenoid 48 is energized it draws its core in and tilts the tubes into their opposite position, when the mercury will immedlately break the circuit in the upper tube and switch off the lights. The circuit through the lower tube Wlll, however, remain closed,

keeping the solenoid energized and the heavy ends of the tubes raised, with the 1115 per circuit open and the lights off, until s cient mercury has run down through the restrlcted passage to uncover the circuit gap in the lower tube;--when the solenoid will be demagnetized and the tubes will drop back to their normal position as shown. The mer cury will then start to run back through the;

wires; and particles of mercury which are dispelled and. deposited upon the wires will eventually dro ofi again and be again picked up by t e rest of the mercury.

I claim as my invention:

A switching device comprising a frame mounted pivotally, automatic means for periodically tilting or oscillating said frame,

V a pluralit of pairs of electric contact sockets on sai frame, demountable switch tubes carried bysaid sockets, said tubes each having spaced terminals and current conducting fluid for opening and closing the circuits respectively, according to the tilt 'of said frame, one of said tubes bein restricted and adapted for slow action and for controlling said automatic means.

Ill

ing connected In witness whereof, I have hereunto subscribed in name this 24 da of Se tember 1915. y p

LOUIS A. M. PHELAN. 

